What did the merchants buy in the colonies for resale in the cities of Greece?

The colonies provided the cities of Greece with what was lacking in Greece itself. For example, merchants in the colonies could buy food products (mainly wheat) for subsequent resale, and wine was also in demand. The trade of the colonies with neighboring tribes made it possible to supply Greece with various handicrafts, animal skins and furs, weapons and equipment. Natural resources were supplied to Greece. The colonies could supply Greece with slaves, who were also supplied by neighboring tribes.